A rotating shaft structure for a screen is used for a foldable portable electronic device. The rotating shaft structure includes a fixing element, a first pivot element, and a second pivot element. The fixing element includes a fixing base and a pivot hole. The fixing base is connected to the foldable portable electronic device. The first pivot element can be pivoted in relation to the fixing element via the pivot hole. The second pivot element is disposed on the fixing element and adjacent to the first pivot element. When the pivoting angle is in a specific pivoting angle range, the first pivot element is pivoted to drive the second pivot element to increase the torsion of the rotating shaft structure.